The specific aims of this proposal are: (1) to isolate the envelope glycoprotein of herpes simplex virus type 2 (HSV-2) and (2) to identify the virion attachment protein(s) of this virus. The envelope glycoproteins will be isolated from infected cell lysates by immunosorbent column chromatography using monoclonal antibodies. The molecular weight of isolated envelope glycoproteins will be checked by SDS-polyacrylamide gel electrophoresis. The effect of each of the glycoproteins on the attachment of HSV-2 virions to human epidermoid carcinoma cells (HEp-2) will be determined by binding studies. The virion attachment protein(s) of HSV-2 will be identified as that envelope glycoprotein which specifically and in a dose-dependent fashion blocks virion binding to HEp-2 cells. The long range objectives of this project are: to isolate the cellular receptor unit for HSV-2 and to evaluate the virion attachment protein(s) and the receptor as possible prophylactic agents against HSV-2 infections.